8527-0544-2M Rev G
APS Enterprise Scale
3
SITE PREPARATION REQUIREMENTS, CONT.
Electrical Power
The APS Enterprise scale is powered by a 100 to 240 VAC 50/60Hz 12 VDC 1A wall plug-in
UL/CSA listed AC power adapter. Note that a special order is not required for operation at
230/240 VAC.
The socket-outlet supplying power to the scale should be on a separate circuit from the
distribution panel and dedicated to the exclusive use of the scale.
The socket-outlet shall be installed near the equipment and shall be easily accessible.
Note that the wall plug-in AC power adapter serves as the power disconnect.
The wiring should conform to national and local electrical codes and ordinances and should
be approved by the local inspector to assure compliance.
On installations requiring 230 VAC power,
it is the responsibility of the customer
to have
a qualified electrician install the proper power adapter plug that conforms to national
electrical codes and local codes and ordinances.
Electrical Noise Interference
To prevent electrical noise interference, make certain all other wall outlets for use with air
conditioning and heating equipment, lighting or other equipment with heavily inductive loads,
such as welders, motors and solenoids are on circuits separate from the scale. Many of these
disturbances originate within the building itself and can seriously affect the operation of the
scale. These sources of disturbances must be identified and steps must be taken to prevent
possible adverse effects on the scale. Examples of available alternatives include isolation
transformers, power regulators, uninterruptible power supplies, or simple line filters.
Transient Suppression
The following recommendations will help to reduce transients:
Always use shielded cables to connect signal wires to the weight scale.
Do not run signal cables from the scale alongside or parallel to wiring carrying AC power. If
unavoidable, position the signal cables a minimum of 24" away from all AC wiring.
Always use arc suppressors across all AC power relay contacts (see recommendations at
http://www.paktron.com/pdf/Quencharch_QRL.pdf).
RFI Immunity
The operation of sensitive electronic equipment can be adversely affected by RF (Radio
Frequency) radio transmissions. Digital weight scales are one such type of equipment. Radio
transmissions come from things like hand-held radio transmitters and cell phones. One
symptom of RFI (Radio Frequency Interference) in a digital weight scale is weight indication
instability during a radio transmission.
The APS Enterprise scale was designed with special grounding and RFI shielding to achieve a
high degree of immunity to common RFI. To maximize the scale’s immunity to radio
transmissions, follow these guidelines:
1.
ALWAYS use shielded cable for all I/O (Input/Output) connections to the scale.
2.
NEVER operate any radio transmitter within 2 meters (~6ft.) of the scale.
3.
NEVER connect un-terminated cables to the scale.
4.
KEEP the intended external I/O devices connected to I/O cables entering the scale.
5.
ALWAYS connect the shield of the shielded I/O cable at the scale end only. Leave the
shield unconnected at the I/O device.
